Ellipses....

[medesigner]

I am trying to machine an ellipse but it is coming out with some fairly large steps in the ellipse. It is coming out like a faceted ellipse....
I have changed the spline deviation, tried arc fitting and nothing seems to help. I don't want to have to change the part to arcs but if I have to I have to. Anybody have any suggestions?

[extanker59]

Can you be more specific? Are the facets just in the graphics or in the part? Are you using 3D or is it a 2D ellipse?

[medesigner]

I am trying to cut from a 3D model. The sketch uses an ellipse though.

[extanker59]

Are you seeing the facets in the actual part or just in the graphics?

[medesigner]

I am seeing them in the part. I adjusted the deviation and it seems to be a bit better though. It is a big ellipse(16" x 6") so I can still some facets but not too bad.

[medesigner]

After adjusting the spline deviation and facet deviation i was able to get the part to come out. Thanks

[extanker59]

You had said that you adjusted your deviation in the first thread. I gather you changed it some more. I usually have my facet and spline deviation set at .0001 and .0002.
What are you at now?

[medesigner]

I had set them to .001 and .002 and it worked fine. Next time i can try a little tighter and see how that works.

[extanker59]

I've tried .001 and .002 but on our small parts it shows up too much. I'm sorry I didn't realize you didn't have it set small already. Could have saved some time if I was smart enough to ask the right questions.